In a conventional electrohydraulic braking system, the brake fluid is injected from a pressure accumulator into the individual wheel cylinders via valves. This pressure accumulator is charged via a pump. If the pump operates continuously, it causes considerable noise emission and disturbs driving comfort. Furthermore, resonance effects can occur under certain operating conditions.
German Patent No. 32 41 039 describes a braking force regulation system that has an anti-lock control system and a power brake unit. In this context, German Patent 32 41 039 describes a method for controlling a pump of an electrohydraulic braking system whereby the hydraulic fluid is injected with control from a pressure accumulator via valve means into the wheel cylinders, the hydraulic fluid being supplied by the pump into the pressure accumulator, and the pump being driven with a mark-to-space ratio that is predefinable according to demand. German Patent No. 32 41 039 also discusses that an advantage of this braking force regulation system is that the noise level is considerably reduced only during operation of the power brake unit. However, the generation of noise is unchanged when the anti-lock control system is activated.